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October
27,
2010 -- 8:55pm EDT
To Stent or Not to Stent: That is the Question!
Last
week saw the latest chapter of the year-and-a-half "Maryland Stent
Story", starring Dr. Mark G. Midei pitted against Towson-based
St. Joseph's Medical Center. Dr. Midei, accused last year by St.
Joe's
of implanting
almost 600 unnecessary coronary stents and relieved of his privileges,
filed a $60 million fraud
lawsuit against the hospital and its parent company. I won't
go into the details because you can read all about it in the Baltimore
Sun's article by Tricia Bishop "Cardiologist
sues hospital over stent allegations" and the, as always,
excellent coverage
by Shelley Wood in theheart.org ("Embattled
Mark Midei speaks: Meets lawsuits by filing his own in "unnecessary-stenting" saga").
Suffice it to say that Dr. Midei does not believe
he implanted stents unnecessarily. And his opinion is backed up
by two Bills (Dr. William O'Neill of University of Miami and Dr.
William Knopf of Piedmont in Atlanta)
who were retained by Midei's legal team to review these cases.
And who are these cardiologists? Well, Dr. O'Neill often has been
quoted on
Angioplasty.Org, because he is one of the true pioneers of interventional
cardiology,
credited with documenting and disseminating the benefits
of primary angioplasty as the "gold standard" of treatment for
heart attacks (see "Heart
Attacks and Angioplasty") -- because of angioplasty and stents, death
from heart attacks has been reduced from 25% fifty years ago
to 2% today! Dr. Knopf likewise is a widely respected interventionalist
who is the COO of the prestigious Piedmont Heart Institute. They
have said that they did not see any "unneeded" procedures.
Of course, St. Joseph's also retained cardiologists
to review the angiograms, among them Dr. Donald Cutlip of Beth Israel Deaconess
in Boston, who disagreed with Midei's decision to stent in a number
of cases. (Dr. Cutlip is the Executive Director of Clinical Investigation
at HCRI, and is widely known for his role in clarifying and setting
the current definitions for "stent thrombosis".)
So is this a "he said; she said" situation? Or is there some scientific
method for determining whether or not a patient needs a stent? One
would hope there is, since angioplasty is now 33 years old!!
Well, of course, there is -- sort of. I revert to "sort
of" because in medicine, we are dealing with human physiology, where
there are very few absolutes. But, in the case of the necessity for
stents, there actually has been research and clinical trials have
been conducted, and the results
were quite clear: in January of 2009, the
FAME study was published...and
it showed that 1/3 of blockages that were judged as "significant"
by looking at an angiogram were, in fact, not significant! Using
Fractional Flow Reserve (FFR) the actual blood flow through the coronary
artery was measured -- and in 1/3 of the cases that looked blocked
on the x-ray, they weren't.
A bit scary -- to see an angiogram that
shows a significant narrowing, and then not stent it? Well the explanation
is a bit complicated, but suffice it to say that flow dynamics
show that just because a two-dimensional shadow image (the kind
produced by an angiogram) implies a narrowing, doesn't mean the
blood flow is actually restricted. And FAME's two year results verify
this -- of the approximately 500 blockages that looked significant
on angiography but were judged not significant via FFR, and were
subsequently NOT TREATED, only
one went on to cause a myocardial infarction: a very low rate of
0.2%. (It is also the case that a blockage that looks insignificant
on an angiogram in fact may be limiting blood-flow and causing
ischemia.)
Unfortunately in the Maryland Stent Story, FFR was not
available at St. Joseph's -- a fact that has also become a point
of controversy: the hospital accuses Dr. Midei of not using FFR technology
but, according to theheart.org
article, Dr. Midei claims:
"...he was the one who had fought SJMC
'tooth and nail' to purchase the FFR technology, and while
he ultimately was successful, the center's FFR program was
not
even up and running the day he was discharged."
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So the take-away here is that FFR has a number of benefits:
one-third less stents, one-third better outcomes -- and should be
used everywhere! Yet only 15% or so of cath labs currently have it
installed.
There are currently two manufacturers of FFR -- Volcano
Corporation and St. Jude Medical (as a result of St. Jude's acquisition
of Radi Medical Systems in 2008). I wrote about this this past summer
in my blog post, "The
Un-Stent Wars: Call Out the Fractional Flow Reserves".
In any case,
one would think that this technology would be more widely used.
Perhaps, as a result of
controversies like Dr.
Midei's, it will be adopted, if only as a way of justifying the
placement, or non-placement, of a stent.
And, oh yeah, benefiting patients
as well!
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